The integration of a molten salt thermal energy storage (TES) system is an effective way to reduce the minimum electricity load rate during the deep shaving process and improve the load cycling rate during the load-up process. However

the potential for power increases of coal-fired power plant (CFPP) during the power-up regulation process is dominated by the maximum output power change of CFPP during the heat discharging process of the molten salt TES system. Six heat discharge schemes including condensate water bypass

boiler feedwater bypass

reheat steam bypass

low-pressure turbine steam injection

medium-pressure turbine steam injection

and high-pressure turbine steam injection are proposed in this study. The performances of heat discharge schemes of molten salt TES systems are analyzed based on a case of a 660 MW supercritical CFPP. Results show that the maximum output power change is affected by the benchmark load rate of CFPP

the maximum split ratio of steam/water mass flow rate

and the maximum mass flow rate of the turbine. The maximum output power changes of low-pressure turbine steam injection

medium-pressure turbine steam injection

and high-pressure turbine steam injection schemes

which are significantly higher than the other schemes

are 14.14%

20.71%

and 25.00% of the rated load under the 75% thermal heat acceptance (THA) condition

respectively. The energy utilization efficiency is affected by the isentropic efficiency of the steam turbine and the average heat absorption temperature of the steam water cycle. The energy conversion efficiency of high-pressure turbine steam injection and reheat steam bypass schemes can reach up to 55.91% and 54.43%

respectively. In comparison

the boiler feedwater bypass and medium-pressure turbine steam injection schemes achieve approximately 40% efficiency

while other schemes fall below 30%. When the temperature of molten salt TES system is above 600℃ and below 450℃

the high-pressure turbine steam injection and low-pressure turbine steam injection schemes obtain the optimal comprehensive performance

respectively.